I don't understand why squatters have any rights at all to begin with
They're supposed to be a check on landowners hoarding property and doing nothing with it, to encourage the productive use of land. In a society where some people own 100s or 1000s of times more assets than other people, sometimes due to nothing more than the situation they were born in, it's too easy for someone with lots of assets to buy up property they don't even need and then just leave it doing nothing while the poor have no place to live. This has been an American principle since the founding, and every state in the country has squatter's rights, red or blue. If you have a bunch of rich landowners buying up all the property in a city without doing anything with it, and the regular people have no place to live, then the city is screwed. Just look at what's happened with the property speculators in Detroit.
It's fascinating that the original justification for squatters rights is more true now than ever. Income inequality is at the highest rate in over 100 years. The racial wealth gap is higher than any time since slavery days. The housing crisis is major, it's never been so hard for a poor person to find a place to live. Housing speculators, both individuals and huge firms, buy up homes like crazy and then either let them sit vacant or just rent them out for a few weekends a year on an Air B&B plan, further exacerbating the housing crisis. You have all the exact ingredients that led to the laws being created in the first place.
But, unfortunately, bootlicking the rich is also at an all-time high, and we live in a society that automatically sees the rich as being more "worthy" than the poor and landowners as having more inherent rights than landless citizens. I don't think they should have arrested her, both because of the bad optics and because I don't think people should be arrested unless necessary (I'd be interested to know why the police chose to arrest in this particular case especially in front of the cameras, when they often find a different way to handle it). But our society really does need checks-and-balances to keep those with assets from hoarding everything while those without assets can't even afford a place to live. Regardless of whether the action was right in this particular case, what would you institute to replace squatter's rights and ensure the rich weren't just leaving homes vacant in places with housing shortages?
Personally for me, I think all residential properties where the owner does not live in the residence should be heavily taxed at a much higher rate than owner-occupied homes.